Honestly, I don't know if you're going to get much in the way of usable answers on this site...in my case, "low" means I start topping off if the vehicle is down a 1/2 quart. Which hasn't happened since I sold the '79 Impala that tended to burn a little oil on longer trips.

I never let my engine run below the middle of the cross hatch, although i have heard plenty of stories of dealerships draining oil burners and only 2 quarts come out of a 4-5 quart sump to know the engine doesn't grenade until it gets really low.

Family had a 77 Nova 250-6 that was very sensitive to oil level.Even if it was full,it would trip the oil light if you drove down a very steep incline.A thorough POS vehicle,that I don't understand why people get so nostalgic about...broken leaf springs,rusted thru shocks,squaky waterpump,5 mufflers,defective carburetor,defective choke thermostat,broken heater control knob,4 batteries,a complete paint job,all in only 5 years of ownership new and 32,000 miles.

Running the sump level to the bottom add line isn't going to affect how the engine lubricates. Oil is still circulating throughout the engine uninterrupted, it's just the reservoir has reached a level that it should be replenished. More sump oil volume doesn't equal better lubrication, but going below the add line may start causing issues...

I had a friend in high school had a 78 Toyota Celica that was making noise. I checked the oil. Nothing on the dipstick. I suggested we just top it off for now. I poured 3 1/2 quarts into it before it ever reached the dipstick. Another quart topped it off. That car went another 200,000 without incident.

A long time ago (I'm embarrassed to admit) I let the oil go low on a 2.2L Chrysler motor and wiped the cam. I should have learned.

Another time I pushed a lawn mower too far. It was due for it's oil change and I hadn't been paying attention to the oil level. I had to mow the yard "one more time". About half way through, the motor slowed and stalled. When you remove the oil fill cap and smoke fumes come out, that's a bad sign. Seized Tecumseh.

I believe that once you reach that point, it spirals downhill and bad things happen fast. The oil level drops to where it can no longer do its job. The oil that remains rapidly becomes overheated and breaks down, plus the contamination. The lubricating system "crashes" and fails to lubricate. Rapid, catastrophic mechanical failure ensues.

That's my confession for today.

I have a friend at work who often says "Any oil is better than NO oil." He's right.I have seen the light. My oil is now meticulously maintained in the upper half of the "run" range.

_________________________
A wise man told me:"Heat is your friend." and "Any oil is better than no oil."

Had an ex-girl friend that had a brand new 1990 Toyota Celica that she ran down to less than 1 quart in it. Engine didn't sound too bad even then. But, about a year later, she told me she traded the car because it was burning oil all the time. Maybe it was a burner to start with, but I can't help but think she did a lot of damage.

The dispdtick defines a conservative safe range for oil level.It is unecessary and wasteful to add oil before the lower line is reached.The OM of my old BMW even says that oil should not be added until the level reaches the add line.The actual safe level is well below the add line on the dipstick.As long as the pickup isn't sucking air, all is well with respect to engine lubrication.The oil pump and the bearings have no idea how much oil remains in the sump, nor do they care as long as they get a steady supply of it rather than air.

I had to laugh when I read this. Just turned 47 last week, and vehicles of these years were in my high school parking lot. From some with smoking blue on startup, exhausts falling off, various road signs used for floor boards and a lot of rust, I don't really miss these vintage of cars, but my first vehicle was a used '78 C10 as a HS grad present from my parents in '85. 2 new doors/fenders and 14 spray cans of blue paint and my truck looked good (as a 18yr. old could do then). It had 72,411 miles on it then and I took it off the road 3 years ago with 337,780 miles on it. It leaked/burnt oil pretty bad near the end, but I really never knew it on how it sounded. Fouled spark plugs gave it away though. It had the equivalent power of my beater '91 Camry four cylinder even though it had a 305 V8. My current Silverado doesn't burn hardly any oil, gets much better mpg and feels twice a strong with 247,000 miles on a 5.3. But I still have feeling for my old truck:)

Originally Posted By: NHGUY

Family had a 77 Nova 250-6 that was very sensitive to oil level.Even if it was full,it would trip the oil light if you drove down a very steep incline.A thorough POS vehicle,that I don't understand why people get so nostalgic about...broken leaf springs,rusted thru shocks,squaky waterpump,5 mufflers,defective carburetor,defective choke thermostat,broken heater control knob,4 batteries,a complete paint job,all in only 5 years of ownership new and 32,000 miles.